High frequency surveying device



J. K. STEWART ETAL 3,293,,W5

HIGH FREQUENCY SURVEYING DEVICE Jan. 17, 1967 2 Sheets-Sheet 1 Filed April 8, 1963 FIG. 4

FIG. 3A

INVENTORS 3 JOHN K. STEWART HELMUTH R. E. VON BECKMANN ATTORNEYS.

1967 J. K. STEWART ETAL 3,298,105

HIGH FREQUENCY SURVEYING DEVICE Filed April 8, 1963 2 Sheets-Sheet 2 GRAVITY SENSITIVE POTENT/OMETER F. H. P.

DRIVE MOTOR /NPUT SIGNAL 06. TO MOTOR FIELD REVERSIBLE POLAR/TY M- D. c. OUTPUT TO MOTOR ARM I FIELD BRIDGE OUTPUT J SUPPLY AMPLIFIER a 5.6. R. FIRING CIRCUIT BY 5W ATTORNEYS.

United States Patent M 3.2%,105 HIGH FREQUENCY SURVEYING DEVICE John K. tewart, 60 Ballantyne Terrace, Dorval, Quebec, Canada, and Helmuth R. E. Von Beckmann, 30 St. Francis Blvd, Chateauguay, Quebec, Canada Filed Apr. 8, 1963, Ser. No. 294,783 Claims priority, application Canada, Feb. 8, 1963, 868,423 11 Claims. (Cl. 33-60) This invention relates to railroad track surveying apparatus. In Canadian Patent No. 650,557 to John K enneth Stewart issued October 16, 1962 there is described the method of surveying a railway track in which an infrared beam transmitter, adapted to project a beam above the grade rail, is mounted for movement along the railway track on a carriage and an infrared beam receiver is mounted above the grade rail for movement along the track in spaced relationship to the transmitter on a tamping and jacking car, a shadow board being located between the transmitter and receiver and adjacent the receiver, which shadow board is mounted on rail engaging wheels. When the grade rail is jacked during a track surfacing operation the shadow board is lifted and interferes with the reception of the transmitter beam thereby actuating means to terminate the jacking. The cross level condition of the other rail relative to the grade rail is detect-ed by a gravity sensor on the shadow board, in this instance a mercury switch. It will be obvious that with the high speed of jacking a tremendously fast response (about milliseconds) is required for the gravity sensor. In Canadian Patent No. 649,411 issued September 25, 1962 to John K. Stewart there is described and claimed another type of gravity sensor, a gyroscope and light beam arrangement, which has a suitably high speed of response.

The present invention removes the necessity of provid ing such a tremendously fast response gravity sensor by providing a railway track surveying apparatus comprising a high frequency beam transmitter mounted for movement along a track and for transmitting a high frequency cone-like beam substantially longitudinally of the track, a pair of beam receivers, one for each rail of the track mounted for movement along the track in spaced relationship to the transmitter within the transmitted cone; shadow means for each receiver mounted for movement along the track and located intermediate the transmitter and receivers and substantially nearer to the receivers than to the transmitters; means for adjusting the vertical height of the receivers; gravity sensing means adapted to control the means for adjusting the vertical height of a selected one of the receivers whereby to maintain one of the receivers in cross level relative to the grade rail.

Thus by removing thegravity sensor from the shadow board and placing it at a position in which it will be subjected to far less violent angular movements and by controlling cross level conditions from a second receiver above the other rail, the necessity for a very fast gravity sensor response is removed.

Additionally, the fact that for jacking operations the time lag induced by the necessity to perform a cross level operation subsequent to sensing the grade rail condition is removed by operating with two receivers so that both rails may be jacked simultaneously resulting in a somewhat faster rate of jacking.

One embodiment of the present invention will now be described with reference to the accompanying drawings in which:

FIGURE 1 is a schematic plan view showing the device on a railway track;

FIGURE 2 is an elevation showing the receivers mounted on a rail engaging frame;

Patented Jan. 17, 1967 ICC FIGURE 3 and 3A are schematic diagrams showing the exaggerated position of the frame in a left hand curve;

FIGURE 4 is a detail of the pendulum and switches; and

FIGURE 5 is a schematic of an alternative form of gravity sensor.

Referring now to the drawings:

A self propelled buggy 10 is provided with a pair of high frequency beam transmitters 11 such as a pair of infra-red beam transmitters, one of which will only be in use at one time, and that, the transmitter above the grade rail. The transmitters 111 transmit a cone of infrared or other high frequency radiation longitudinally along the track towards the carriage 1.4. The carriage 14 is preferably a jacking and tamping car and has a pair of receivers 15a, 15!) mounted on the frame 16 which is in turn mounted with the rear axle 17 of the car 14. Thus the frame 16 is mounted for movement along the track in spaced relation to the transmitter and within the transmitted cone. Of course it is to be understood that the frame could be supported for movement along the track independently of the jacking and tamping car carriage 14. A pair of shadow boards 20, one for each receiver, are mounted on rail engaging wheels 21 on a frame 22 which is connected to the front of the car 14. Thus, the shadow boards are mounted for movement along the track and located intermediate of the transmitter and receiver and preferably nearer the receivers than the transmitter.

Means are provided for adjusting the vertical height of the receivers so as to maintain the receiver associated with the non grade rail in cross level condition relative to the receiver associated with the grade rail. While various arrangements can be employed, in the disclosed construction receivers 15a, 1512 are connected to the frame 16 through a pair of screw jacks 24a, 24b, operated by the motors 26 and 26b mounted on the frame 16 to raise and lower the receivers. Pivotally connected at its ends to the brackets 30 on which the receivers 15a, 15b, are mounted is a cross bar 31. At the center of the cross bar there is provided a casing 3-4 braced by struts 35, 36, in which there is provided a gravity sensing means for controlling the means for adjusting the vertical height of the receivers. While various arrangements can be employed in the construction shown in FIGURE 2, a pendulum 37 is pivotally mounted at 38. Mounted Within the casing 34 are micro switches 39 and 40 the positions of which are adjusted relative to the casing 34, for calibration, by screws 41, 42.

As will be seen in FIGURE 2, and as seen from behind when the frame is on tangent track the pendulum is directly up and down and makes no contact with the switches 39 and 40. However when the car 14 enters a curve, say the left hand curve as illustrated in FIG- URES 3 and 3A the pendulum swings towards the grade rail, that is, the left hand rail, and makes the switch 39 to operate the motor 26b to cause the screw jack 24b to turn and lower the receiver 151; until it is in cross level relative to the grade rail so that the receivers 15a and 15b remain in a common horizontal plane.

It must be understood that the term cross level to the grade rail as used herein, is intended to define an actual geographical condition, wherein the receivers are either maintained in a common horizontal plane or are maintained in horizontal planes the spacing of which does not vary substantially. The condition diagrammatic-ally shown in FIGURE 3A is one which could be assumed by a modification of the arrangement shown in FIGURE 2 in which the receivers (and their associated shadow boards) are located in horizontal planes spaced apart by a distance N. The spacing N is substantially maintained regardless of whether the receivers are on tangent or curved track.

It will be obvious that in a right hand curve the motor 26 will operate the screw jack 24a to make the necessary adjustment to the receiver 15a.

Clearly any other gravity sensor device could be used and an example of another preferred form is seen in F1- URE 5. It consists essentially of two main partsa gravity sensing electrolytic potentiometer and bridge 51, and a phase sensitive amplifier 52. The gravity sensing potentiometer may be mounted in a casing similar to the casing 34 and mounted on the cross bar in a fashion similar to that shown in FIGURE 2. The gravity sensitive potentiometer 51 is used in a bridge circuit and provides a phase sensitive A.C. signal when misaligned from the horizontal. The phase sensitive amplifier 52 provides a positive or negative DC. output depending upon the phase of the signal from the potentiom ter 51 (depending upon the direction of tilt of the potentiometer 51) and this DC. output is applied to a bridge 53. The output from the bridge 55 controls the motors 26 and 26b which may be simple reversible D.C. shunt wound motors.

The embodiment of FEGURE 5 has the added advantage that ,it is more rugged and less sensitive to vibration than is the pendulum device of FIGURE 4. This is particularly true when the majority of the components of the embodiment of FTGURE 5 may be encased in epoxy resin. Furthermore the compactness of this assembly enables the encased components Sli, 52, 53 and a field supply 55 to be enclosed in a casing such as casing 34.

The receivers a andldb operate through a suitable circuit such as for example disclosed in Canadian Patent No. 646,048 issued July 31, 1962, inventor lo-hn Kenneth Stewart to control the jacking operation for the individual rail over which they are positioned. Thus if both shadow boards open the receivers 15:: and 15b to the transmitted 'beam then both rails will be jacked and when one receiver has been obscured from the transmitted beam by the raising of its shadow board into the beam, the jacking of the associated rail will be terminated. Two transmitters 11 are provided one above each rail and are switched so that only the one above the grade rail is the one which is operated.

Shadow board adjustment for selection of lift and/0r super-elevation is according to standard procedures such as described in aforementioned Canadian Patent No. 650,557.

What we claim as our invention is:

1. Railway track surveying apparatus including at least one high frequency beam transmitter mounted for move ment along a track and for transmitting a high frequency cone-like beam substantially longitudinally of the track, a pair of beam receivers, one for each rail of the track mounted for movement along the track in spaced relationship to the transmitter within the transmitted cone; shadow means for each receiver mounted for movement along the track and located intermediate the transmitter and receivers and substantially nearer to the receivers than to the transmitter; means for adjusting the vertical height dof the receivers; gravity sensing means for controlling the means for adjusting the vertical height of one of the receivers whereby to maintain the receivers in cross level relative to the grade rail.

2. Apparatus as claimed in 1 in which the high frequency beam is an infra red beam.

3. Apparatus as claimed in claim 1 in which each receiver is located directly above its associated rail and the transmitter is located directly above the grade rail.

4. Apparatus as claimed in claim 1 in which the means for adjusting the vertical height of the receivers cornprises a motor driven screw jack.

5. Apparatus as claimed in claim 1 in w ich the gravity sensing means comprises a pendulum.

6. Apparatus as claimed in claim 1 in which the gravity sensing means comprises a gravity sensing potentiometer.

7. Apparatus as claimed in claim 1 in which the receivers are mounted on a frame for independent vertical height adjustment and are each pi'votally connected to a common cross bar which carries the gravity sensing means.

8. Apparatus as claimed in claim 7 in which each receiver is connected to the frame through a motor driven screw jack.

9. Apparatus as claimed in claim 8 in which the gravity sensing means is a pendulum housed in a casing attached to the cross bar, switch means being provided within the casing adapted to be operated by contact with the penduil um to actuate a selected motor driven screwjack.

10. Apparatus as claimed in claim 8 in which the gravity sensing means is a gravity sensing potentiometer and is housed in a casing attached to the cross bar.

11. Railway track surveying apparatus including one high frequency beam transmitter mounted for movement along a track and for transmitting a high frequency conelike beam substantially longitudinally of the track, a pair of beam receivers, one for each rail of the track mounted for movement along the tr'ack'in spaced relationship to the transmitter within the transmitted cone; shadow means for each receiver mounted for movement along the track and located intermediate the transmitter and receivers and substantially nearer to the receivers than to the transmitter; means for adjusting the vertical height of the receivers; gravity sensing means for control-ling the means for adjusting the vertical height of the receivers whereby to maintain the receivers in cross level relative to the grade rail.

References Cited by the Examiner UNlTED STATES PATENTS 3,060,099 9/1961 Hayes 336O FOREIGN PATENTS 650,557 10/1962 Canada.

LEONARD FORMAN, Primary Examiner.

LEO QUACKENBUSH, Examiner.

M. I. HILL, HARRY N. HAROIAN,

Assistalzl Examiners. 

1. RAILWAY TRACK SURVEYING APPARATUS INCLUDING AT LEAST ONE HIGH FREQUENCY BEAM TRANSMITTER MOUNTED FOR MOVEMENT ALONG A TRACK AND FOR TRANSMITTING A HIGH FREQUENCY CONE-LIKE BEAM SUBSTANTIALLY LONGITUDINALLY OF THE TRACK, A PAIR OF BEAM RECEIVERS, ONE FOR EACH RAIL OF THE TRACK MOUNTED FOR MOVEMENT ALONG THE TRACK IN SPACED RELATIONSHIP TO THE TRANSMITTER WITHIN THE TRANSMITTED CONE; SHADOW MEANS FOR EACH RECEIVER MOUNTED FOR MOVEMENT ALONG THE TRACK AND LOCATED INTERMEDIATE THE TRANSMITTER AND RECEIVERS AND SUBSTANTIALLY NEARER TO THE RECEIVERS THAN TO THE TRANSMITTER; MEANS FOR ADJUSTING THE VERTICAL HEIGHT OF THE RECEIVERS; GRAVITY SENSING MEANS FOR CONTROLLING THE MEANS FOR ADJUSTING THE VERTICAL HEIGHT OF ONE OF THE RECEIVERS WHEREBY TO MAINTAIN THE RECEIVERS IN CROSS LEVEL RELATIVE TO THE GRADE RAIL. 